So...since our Duolingo lady had such a bad rep...I guess they switched her? I like the new one because it seems much more fluid on her part. But in this excercise Im fairly certain she just said Cloisi[mwid]...is that correct too? And then across the board or just this verb..?
She is saying 'cloiseann muid'. This form (known as 'analytic', in contrast to the 'synthetic' version 'cloisimid'), is an acceptable alternative across the board for the first person plural in the present tense. It is one of those things that vary according to regional dialect.
In the past, synthetic forms were more widespread, and they are more common in Munster. For example, I have friends who will commonly use 'bhíos' (= 'bhí mé'), as well as third-person plurals in the aimsir caite ending in -adar, e.g. 'thángadar' (='tháinig siad'). Some interesting stuff on this topic here: http://www.gaeilge.org/synthetic.html
I don't think the issue is that the phrase doesn't seem useful more so that the construct doesn't seem useful and thus leaves me (and I assume other learners) feeling like they are missing something. That's the entire prepositions 3 section for me.
A useless phrase like "Itheann an t-úll an béar" wouldn't bother me because while I know apples can't eat bears, it's clear what the sentence is asserting; the sentence is semantically meaningful while due to the absurdity of what it asserts, it's not a useful phrase. That's really straight-forward because of the one-one mapping between nouns and verbs from one language to the next. (Frankly I wish there were more sentences like this because it would better test understanding of the constructs than recognition of the phrases that have been used repeatedly.)
However when encountering a phrase with prepositions that seems semantically "odd" in English such as "Tá fuithi éisteacht leis an raidio"-> "There is under her listen with the radio", it's generally a signal that due to the fact that prepositions don't translate between languages, there are idioms afoot. So in this case "She intends to listen to the radio" ends up making clear that "tá faoi____" indicates something's intention and "éisteacht leis" is used where English would use "listen to". Note that if "raidio" were replaced in that sentence with an odd noun like "síosúr" as to make the phrase not useful, it wouldn't detract from it's pedagogical value.
A sentence like "cloisimid madra eadraibh" on the other hand triggers that same "odd prepositional phrase" signal but then the given translation still seems odd making me feel like I'm missing some meaning of "idir".
Most of the lessons thus far have been wonderful. This one, for me at least, seems like it could be a bit better.
Maybe this is a disconnect between the course creators and me (and based on this thread other learners as well) as again, it's not clear what "X hears Y between you" means in the dialect of English I speak. I have seen other lessons where either the lesson or mods explained that the English translation used in the exercise was idiomatic to a particular dialect that apparently most of the learners aren't familiar with.
Edited to add (since more comments are coming in but I can't reply to them): Sure. You can really contort the sentence to have a spatial or temporal meaning but the point still stands that those aren't natural constructs. E.g. in the temporal case one would say something more like "I hear X in between hearing Y and Z". They wouldn't use "I hear X between P" (where P is a plural word).
That's all besides the point though. Using the same logic, if a learner encountered the sentence "Tá lacha uait" for the first time they would think something like: "Oh the ducks are from you. Like you sent these ducks." Instead, most learners by now have realized the prepositional phrases have a lower chance of translating directly therefore, especially when they encounter a sentence that is as odd as this one, they will tend to think of it as being an idiom. If you are already an Irish expert then it's obvious to you that it's not an idiom and you thus default to contorting a meaning out of the sentence. Learners don't have that advantage. Go through the discussion pages of the exercises from this section and you'll see similar confusion throughout. The point is that pedagogically speaking some of the sentences in this section are suboptimal.
None of that is meant as an affront to all the work that's gone into this course. It's literally just feedback (that doesn't have to be acted upon) in case the course creators are interested in improving the course. The course is wonderful so far but, like with anything else, there is always room for improvement and getting the perspective of a learner should be helpful for experts interested in doing so.
Linguistically, our brains "fill in the blanks" when listening which allows us to "hear" when there is noise getting in the way. But, that relies on the probability that the word filled in makes the most sense. I object to grammatically correct nonsense because it provides no preparation for listening to the real language being broadcast from Ireland. The main contribution I get from Duolingo is just vocabulary and a minor amount of idiom. The pronunciation is less than helpful because I do listen to live interviews and programs over the Internet.